Many structures, both mobile and fixed, have excess interior portions that are unused under normal conditions. For example, many sport utility vehicles presently on the market usually carry only a single occupant (the driver) and are only occasionally filled with passengers or cargo. Consequently, large interior portions of such vehicles typically remain vacant and unused. Other examples of unoccupied structural portions are the many rooms and open areas that remain vacant in buildings pending future expansion, lease agreements, new employees, and special occasions.
Heating and cooling the air masses within these unused interior portions of structures wastes a significant amount of energy, particularly when the structures"" occupied portions undergo temperature changes throughout periods of use. When the driver and sole occupant of a conventionally equipped sport utility vehicle begins an afternoon commute in hot weather, for example, the driver is typically forced to turn on the vehicle""s air conditioning at its maximum setting to cool the entire interior of the vehicle. Even though the driver is only concerned about cooling the front portion of the vehicle (the area in his or her immediate vicinity), convection throughout the vehicle""s open interior limits the temperature difference between the front and rear portions. Similarly, the heating and cooling system of an xe2x80x9copen officexe2x80x9d (a portion of a structure having cubicles instead of permanent dividing walls) must heat and cool substantially the entire air mass of the open office even though portions of the open office (e.g., certain cubicles) may be unoccupied.
Often, even steady-state heating and cooling of air masses within unused interior portions wastes energy. When an unused portion is adjacent an exterior wall of a structure, heat conducts (through the exterior wall) between the unused portion and outside air surrounding the structure.
In many conventional air conditioning systems, such as automobile air conditioning units, the efficiency (and the rate of energy consumption) depends greatly on the rate of cooling. Convection between occupied and unoccupied portions of an automobile can require its air conditioning system to operate at a high cooling rate (and a correspondingly low efficiency rate) for more time than would be necessary just to cool the occupied portion.
Consequently, a need remains for substantially preventing convection between the air masses of vacant and occupied portions of structures. A further need remains for selectively preventing and permitting such convection when portions of structures undergo transitions between vacant and occupied states.
In accordance with aspects of the present invention, including various advantageous methods, an air mass within a first portion of a structure is isolated from an adjacent air mass within a second portion of the structure. When isolation is desired, an air container substantially occupies the first portion of the structure and substantially prevents convection between the air masses within the first and second portions of the structure. When isolation is not desired, the air container vacates the first portion. The air container can inflate within the structure""s first portion to substantially occupy it, and can deflate to vacate the portion. Alternatively, the air container can be brought into and out of the first portion to substantially occupy and vacate the portion, respectively.
By preventing convection between adjacent air masses (one of which may largely or completely surround the other), an air container according to various aspects of the invention restricts heat transfer between the air masses. Advantageously, one air mass can achieve a desired temperature faster and more efficiently when the air container restricts heat transfer from that air mass to an adjacent, unused air mass.
A particularly advantageous air container according to various aspects of the invention includes a semi-rigid, substantially air-impermeable shell that is collapsible to a predetermined collapsed shape and expandable to a predetermined expanded shape. The air container can further include a selective air passage that permits air to enter the shell when it expands. The air passage can be selectably opened to permit air to exit the shell when the shell is to be collapsed.
A method of the invention particularly enhances efficiency and speed of heating and cooling within a vehicle (especially a van or sport utility vehicle). In the method, an air container of the invention is placed in a rear seating portion or cargo portion of the vehicle. Advantageously, the air container can be dimensioned to fit, when fully inflated, in the rear seating or cargo portion with substantially all of its enclosed volume below the level of the vehicle""s rear window.
The above summary does not include an exhaustive list of all aspects of the present invention. Indeed, the inventor contemplates that his invention includes all systems and methods that can be practiced from all suitable combinations of the various aspects summarized above, as well as those disclosed in the detailed description below and particularly pointed out in the claims filed with the application. Such combinations have particular advantages not specifically recited in the above summary.